1. Field
The present disclosure relates to a nitride-based semiconductor substrate having a buffer layer where a hollow member pattern is formed, and to a method of fabricating the nitride-based semiconductor substrate.
2. Description of the Related Art
In general, AlGaInN-based nitride semiconductors (including GaN-based) having a light emitting wavelength ranging from an ultraviolet ray to a visible ray and having superior chemical and thermal stability are used as a higher temperature, higher output electronic element. The electronic element may include light emitting diodes or laser diodes.
However, it is relatively difficult to obtain a large-scale GaN single crystal substrate to grow a nitride-based semiconductor. Thus, heterogeneous substrates, such as sapphire, silicon, or silicon carbide (SiC), are used for this purpose. When a nitride-based semiconductor grows on a heterogeneous substrate, a greater amount of strain and stress are generated on a relatively thin film that grows thereon due to a difference in a lattice constant and a thermal expansion coefficient between the heterogeneous substrate and the thin film. Thus, the thin film is not grown as well on a heterogeneous substrate. And, even when the thin film does grow, the defect density is higher in the thin film and/or cracks may be generated in the thin film. The defect may become a non-light emitting area or a path for leakage current such that the optical and electric properties of a device using the nitride-based semiconductor may be deteriorated.